wlr layer shell

Create a layer surface for an existing surface. This assigns the role of layer_surface, or raises a protocol error if another role is already assigned.

Creating a layer surface from a wl_surface which has a buffer attached or committed is a client error, and any attempts by a client to attach or manipulate a buffer prior to the first layer_surface.configure call must also be treated as errors.

After creating a layer_surface object and setting it up, the client must perform an initial commit without any buffer attached. The compositor will reply with a layer_surface.configure event. The client must acknowledge it and is then allowed to attach a buffer to map the surface.

You may pass NULL for output to allow the compositor to decide which output to use. Generally this will be the one that the user most recently interacted with.

Clients can specify a namespace that defines the purpose of the layer surface.

This request indicates that the client will not use the layer_shell object any more. Objects that have been created through this instance are not affected.

These values indicate which layers a surface can be rendered in. They are ordered by z depth, bottom-most first. Traditional shell surfaces will typically be rendered between the bottom and top layers. Fullscreen shell surfaces are typically rendered at the top layer. Multiple surfaces can share a single layer, and ordering within a single layer is undefined.

Sets the size of the surface in surface-local coordinates. The compositor will display the surface centered with respect to its anchors.

If you pass 0 for either value, the compositor will assign it and inform you of the assignment in the configure event. You must set your anchor to opposite edges in the dimensions you omit; not doing so is a protocol error. Both values are 0 by default.

Size is double-buffered, see wl_surface.commit.

Requests that the compositor anchor the surface to the specified edges and corners. If two orthogonal edges are specified (e.g. 'top' and 'left'), then the anchor point will be the intersection of the edges (e.g. the top left corner of the output); otherwise the anchor point will be centered on that edge, or in the center if none is specified.

Anchor is double-buffered, see wl_surface.commit.

Requests that the compositor avoids occluding an area with other surfaces. The compositor's use of this information is implementation-dependent - do not assume that this region will not actually be occluded.

A positive value is only meaningful if the surface is anchored to one edge or an edge and both perpendicular edges. If the surface is not anchored, anchored to only two perpendicular edges (a corner), anchored to only two parallel edges or anchored to all edges, a positive value will be treated the same as zero.

A positive zone is the distance from the edge in surface-local coordinates to consider exclusive.

Surfaces that do not wish to have an exclusive zone may instead specify how they should interact with surfaces that do. If set to zero, the surface indicates that it would like to be moved to avoid occluding surfaces with a positive exclusive zone. If set to -1, the surface indicates that it would not like to be moved to accommodate for other surfaces, and the compositor should extend it all the way to the edges it is anchored to.

For example, a panel might set its exclusive zone to 10, so that maximized shell surfaces are not shown on top of it. A notification might set its exclusive zone to 0, so that it is moved to avoid occluding the panel, but shell surfaces are shown underneath it. A wallpaper or lock screen might set their exclusive zone to -1, so that they stretch below or over the panel.

The default value is 0.

Exclusive zone is double-buffered, see wl_surface.commit.

Requests that the surface be placed some distance away from the anchor point on the output, in surface-local coordinates. Setting this value for edges you are not anchored to has no effect.

The exclusive zone includes the margin.

Margin is double-buffered, see wl_surface.commit.

Set how keyboard events are delivered to this surface. By default, layer shell surfaces do not receive keyboard events; this request can be used to change this.

This setting is inherited by child surfaces set by the get_popup request.

Layer surfaces receive pointer, touch, and tablet events normally. If you do not want to receive them, set the input region on your surface to an empty region.

Keyboard interactivity is double-buffered, see wl_surface.commit.

This assigns an xdg_popup's parent to this layer_surface. This popup should have been created via xdg_surface::get_popup with the parent set to NULL, and this request must be invoked before committing the popup's initial state.

See the documentation of xdg_popup for more details about what an xdg_popup is and how it is used.

When a configure event is received, if a client commits the surface in response to the configure event, then the client must make an ack_configure request sometime before the commit request, passing along the serial of the configure event.

If the client receives multiple configure events before it can respond to one, it only has to ack the last configure event.

A client is not required to commit immediately after sending an ack_configure request - it may even ack_configure several times before its next surface commit.

A client may send multiple ack_configure requests before committing, but only the last request sent before a commit indicates which configure event the client really is responding to.

This request destroys the layer surface.

Change the layer that the surface is rendered on.

Layer is double-buffered, see wl_surface.commit.

Requests an edge for the exclusive zone to apply. The exclusive edge will be automatically deduced from anchor points when possible, but when the surface is anchored to a corner, it will be necessary to set it explicitly to disambiguate, as it is not possible to deduce which one of the two corner edges should be used.

The edge must be one the surface is anchored to, otherwise the invalid_exclusive_edge protocol error will be raised.

The configure event asks the client to resize its surface.

Clients should arrange their surface for the new states, and then send an ack_configure request with the serial sent in this configure event at some point before committing the new surface.

The client is free to dismiss all but the last configure event it received.

The width and height arguments specify the size of the window in surface-local coordinates.

The size is a hint, in the sense that the client is free to ignore it if it doesn't resize, pick a smaller size (to satisfy aspect ratio or resize in steps of NxM pixels). If the client picks a smaller size and is anchored to two opposite anchors (e.g. 'top' and 'bottom'), the surface will be centered on this axis.

If the width or height arguments are zero, it means the client should decide its own window dimension.

The closed event is sent by the compositor when the surface will no longer be shown. The output may have been destroyed or the user may have asked for it to be removed. Further changes to the surface will be ignored. The client should destroy the resource after receiving this event, and create a new surface if they so choose.

Types of keyboard interaction possible for layer shell surfaces. The rationale for this is twofold: (1) some applications are not interested in keyboard events and not allowing them to be focused can improve the desktop experience; (2) some applications will want to take exclusive keyboard focus.